Methods for cleaning industrial equipment with pre-treatment

ABSTRACT

A method of cleaning equipment such as heat exchangers, evaporators, tanks and other industrial equipment using clean-in-place procedures and a pre-treatment solution prior to the conventional CIP cleaning process. The pre-treatment step improves the degree of softening of the soil, and thus facilitates its removal. The pre-treatment solution can be a strong acidic solution, a strong alkaline solution, or comprise a penetrant. A preferred strong acidic solution is an acid peroxide solution. In some embodiments, the pre-treatment may include no strong alkali or acid ingredient; rather, the penetrant provides acceptable levels of pre-treatment.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 10/928,774 titled METHODS FOR CLEANING INDUSTRIAL EQUIPMENTWITH PRE-TREATMENT, filed on Aug. 27, 2004, the complete disclosure ofwhich is incorporated herein by reference in its entirety.

FIELD

The invention relates to cleaning of industrial equipment such asevaporators, heat exchangers and other such equipment that isconventionally cleaned using a CIP (clean-in-place) process.

BACKGROUND

In many industrial applications, such as the manufacture of foods andbeverages, hard surfaces commonly become contaminated with soils such ascarbohydrate, proteinaceous, and hardness soils, food oil soils andother soils. Such soils can arise from the manufacture of both liquidand solid foodstuffs. Carbohydrate soils, such as cellulosics,monosaccharides, disaccharides, oligosaccharides, starches, gums andother complex materials, when dried, can form tough, hard to removesoils, particularly when combined with other soil components such asproteins, fats, oils and others. The removal of such carbohydrate soilscan be a significant problem. Similarly, other materials such asproteins, fats and oils can also form hard to remove soil and residues.

Food and beverage soils are particularly tenacious when they are heatedduring processing. Foods and beverages are heated for a variety ofreasons during processing. For example, in dairy plants, dairy productsare heated on a pasteurizer (e.g. HTST—high temperature short timepasteurizer or UHT—ultra high temperature pasteurizer) in order topasteurize the dairy product. Also, many food and beverage products areconcentrated or created as a result of evaporation.

Specific examples of food and beverage products that are concentratedusing evaporators include dairy products such as whole and skimmed milk,condensed milk, whey and whey derivatives, buttermilk, proteins, lactosesolutions, and lactic acid; protein solutions such as soya whey,nutrient yeast and fodder yeast, and whole egg; fruit juices such asorange and other citrus juices, apple juice and other pomaceous juices,red berry juice, coconut milk, and tropical fruit juices; vegetablejuices such as tomato juice, beetroot juice, carrot juice, and grassjuice; starch products such as glucose, dextrose, fructose, isomerose,maltose, starch syrup, and dextrine; sugars such as liquid sugar, whiterefined sugar, sweetwater, and insulin; extracts such as coffee and teaextracts, hop extract, malt extract, yeast extract, pectin, and meat andbone extracts; hydrolyzates such as whey hydrolyzate, soup seasonings,milk hydrolyzate, and protein hydrolyzate; beer such as de-alcoholizedbeer and wort; and baby food, egg whites, bean oils, and fermentedliquors.

There are generally at least two sides to an evaporator. One side holdsthe steam or vapor heat source (typically 212° F. to 350° F.). The otherside holds the process liquid to be concentrated. During the evaporationprocess, the liquid to be concentrated is introduced into theevaporator. The heat exchange across the tubes or plates evaporateswater off the process stream concentrating the liquid solids. The liquidto be concentrated may be run through an evaporator several times untilit is sufficiently concentrated.

There are many different types of evaporators including falling filmevaporators, forced circulation evaporated evaporators, plateevaporators, circulation evaporators, fluidized bed evaporators, fallingfilm short path evaporators, rising film evaporators,counterflow-trickle evaporators, stirrer evaporators, and spiral tubeevaporators. In addition to the evaporators, there are several otherpieces of equipment in an evaporation plant including preheaters andheaters, separators, condensers, deaeration/vacuum systems, pumps,cleaning systems, vapor scrubbers, vapor recompression systems, andcondensate polishing systems. All of the evaporation plant equipmentshould be cleaned, however, the actual evaporator typically has the mostdifficult soiling problems.

When a food or beverage product contacts any surface, soiling occurswhere some part of the food or beverage product is left behind on thatsurface. When that surface is a heat exchange surface, the soil becomesthermally degraded rendering it even more difficult to remove. Overtime, the layer of soil increases in thickness as more food or beverageproduct is passed over the heat exchange surface. The layer of soil actsas an insulator between the heat and the product being heated, therebyreducing the efficiency of the heat exchange surface and requiring moreenergy to create the same effect if the heat exchange surface wereclean. When the heat exchange surface is an evaporator, the differencebetween a clean heat exchange surface and a soiled heat exchange surfacecan mean the difference in millions of dollars in energy costs for anevaporator plant. With the cost of energy increasing significantly, aswell as an increased awareness of protecting the environment bypreserving natural resources, there remains a need for cleaning programsthat can clean heat exchange surfaces and create an efficient transfer aheat.

Clean-in-place cleaning techniques are a specific cleaning regimenadapted for removing soils from the internal components of tanks, lines,pumps and other process equipment used for processing typically liquidproduct streams such as beverages, milk, juices, etc. Clean-in-placecleaning involves passing cleaning solutions through the system withoutdismantling any system components. The minimum clean-in-place techniqueinvolves passing the cleaning solution through the equipment and thenresuming normal processing. Any product contaminated by cleaner residuecan be discarded. Often clean-in-place methods involve a first rinse,the application of the cleaning solutions, a second rinse with portablewater followed by resumed operations. The process can also include anyother contacting step in which a rinse, acidic or basic functionalfluid, solvent or other cleaning component such as hot water, coldwater, etc. can be contacted with the equipment at any step during theprocess. Often the final portable water rinse is skipped in order toprevent contamination of the equipment with bacteria following thecleaning and/or sanitizing step.

Clean-in-place processing requires a complete or partial shutdown of theequipment being cleaned, which results in lost production time. Manytimes, the equipment is not thoroughly cleaned, due to the largedowntime needed. What is needed is an improved method for cleaning thisequipment, using the clean-in-place process, which uses less time tothoroughly remove the soils.

It is against this background that the present invention has been made.

SUMMARY OF THE DISCLOSURE

Surprisingly, it has been discovered that food and beverage soils, andespecially baked-on food and beverage soils can be removed from surfacesusing a two-step method where the soil is contacted with a pre-treatmentcomposition in a pre-treatment step, followed by a conventionalclean-in-place process. The invention relates to methods of cleaningequipment such as heat exchangers, evaporators, tanks and otherindustrial equipment using clean-in-place procedures. The method issuitable for organic soil removal or, more particularly, for food orbeverage soil removal. Further, the method relates to cleaning processesfor removing carbohydrate and proteinaceous soils from food and beveragemanufacturing locations using a clean-in-place method.

In one aspect, the invention is directed to a method that includespre-treating the soiled surfaces with a strong acidic solution. Aconventional clean-in-place process follows this pre-treatment step. Apreferred acidic solution is an acid peroxide solution. It has beenfound that a conventional clean-in-place process using an alkalinedetergent after the acidic pre-treatment step provides particularlyeffective results. The concentration of the active ingredients in anacidic pre-treatment solution for some applications is at least 0.1% andusually at least 0.6%.

In another aspect, the invention is directed to a method that includespre-treating the soiled surfaces with a strong alkaline solution. Aconventional clean-in-place process follows this pre-treatment step. Ithas been found that a conventional clean-in-place process using anacidic detergent after the strong alkaline pre-treatment step providesparticularly effective results.

Either of the pre-treatments, either acidic or alkaline, may include apenetrant. The addition of a penetrant improves the degree of softeningof the soil, and thus facilitates the removal of the soil. Theconcentration of penetrant in a pre-treatment solution is at least 0.01and usually at least 0.15%. A concentration of about 1% is acceptable.

In another aspect, the invention is directed to a method that includespre-treating the soiled surfaces with a penetrant, without the presenceof appreciable amounts of acid or alkaline. A conventionalclean-in-place process follows this penetrant pre-treatment step. Here,the concentration of penetrant in the pre-treatment solution (withoutacid or alkalinity) is at least 0.01% and usually is at least 0.15%. Inone particular embodiment, the penetrant pre-treatment solutioncomprises approximately 0.9% of solvents; other levels of solvents aspenetrants are suitable.

In one particular embodiment, the invention is a method of cleaningsoils from industrial equipment using a CIP process. The method includesapplying a pre-treatment solution to the soil, the solution comprisingat least 0.25 wt-% active ingredients, with the active ingredientsincluding any of an alkaline source, an acidic source, a penetrant, anoxidizer, and a builder. The method also includes recirculating a firstCIP solution through the equipment after the pre-treatment solution, theCIP solution comprising a dilute detergent and then rinsing theequipment. The pre-treatment solution can have 0.25 to 1.5 wt-% acidand/or 0.01 to 1 wt-% oxidant, such as a peroxide. A penetrant, such asglycol ether, may be present at 0.4 to 10 wt-%.

In another particular embodiment, the method includes pre-treating thesoil with a pre-treatment solution comprising at least 0.5 wt-% activeingredients, the active ingredients including any of an alkaline source,an acidic source, a penetrant, an oxidizer, a surfactant, and a builder,removing at least a portion of the penetrated soil with a dilutedetergent solution, and rinsing the equipment. In some embodiments, thepre-treatment solution includes an alkaline source and the dilutedetergent includes an acid. In other embodiments, the pre-treatmentsolution includes an acid source and the dilute detergent is alkaline.

The present invention includes using two different CIP solutions.

These and other embodiments will be apparent to these of skill in theart and others in view of the following detailed description. It shouldbe understood, however, that this summary and the detailed descriptionillustrate only some examples, and are not intended to be limiting tothe invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an industrial process that includesequipment to be cleaned, CIP process equipment, and pre-treatmentequipment.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to cleaning of industrial equipmentusing a pre-treatment step in combination with clean-in-placeprocedures. Use of a pre-treatment step, in combination withconventional clean-in-place solutions and processes, provides increasedsoil removal than the conventional process alone. Additionally, use of apre-treatment step, followed by a water rinse, provided unexpectedamounts of soil removal. Use of a pre-treatment step allows the use oftraditionally incompatible chemistries and at higher concentrations thenapplied in conventional cleaning programs.

As used herein, “weight percent”, “wt-%”, “percent by weight”, “% byweight”, and variations thereof refer to the concentration of asubstance as the weight of that substance divided by the total weight ofthe composition and multiplied by 100. It is understood that, as usedhere, “percent”, “%”, and the like are intended to be synonymous with“weight percent”, “wt-%”, etc.

As used herein, the term “about” refers to variation in the numericalquantity that can occur, for example, through typical measuring andliquid handling procedures used for making concentrates or use solutionsin the real world; through inadvertent error in these procedures;through differences in the manufacture, source, or purity of theingredients used to make the compositions or carry out the methods; andthe like. The term “about” also encompasses amounts that differ due todifferent equilibrium conditions for a composition resulting from aparticular initial mixture. Whether or not modified by the term “about”,the claims include equivalents to the quantities.

It should be noted that, as used in this specification and the appendedclaims, the singular forms “a,” “an” and “the” include plural referentsunless the content clearly dictates otherwise. Thus, for example,reference to a composition containing “a compound” includes having twoor more compounds. It should also be noted that the term “or” isgenerally employed in its sense including “and/or” unless the contentclearly dictates otherwise.

The method of the present invention applies to equipment generallycleaned using clean-in-place (i.e., CIP) cleaning procedures. Examplesof such equipment include evaporators, heat exchangers (includingtube-in-tube exchangers, direct steam injection, and plate-in-frameexchangers), heating coils (including steam, flame or heat transferfluid heated) re-crystallizers, pan crystallizers, spray dryers, drumdryers, and tanks. This method can be used in generally any applicationwhere caked on soil or burned on soil, such as proteins orcarbohydrates, needs to be removed; applications include the food andbeverage industry (especially dairy), brewing, oil processing,industrial agriculture and ethanol processing.

CIP processing is generally well-known. The process includes applying adilute solution (typically about 0.5-3%) onto the surface to be cleaned.The solution flows across the surface (3 to 6 feet/second), slowlyremoving the soil. Either new solution is re-applied to the surface, orthe same solution is recirculated and re-applied to the surface.

A typical CIP process to remove a soil (including organic, inorganic ora mixture of the two components) includes at least three steps: analkaline solution wash, an acid solution wash, and then a fresh waterrinse. The alkaline solution softens the soils and removes the organicalkaline soluble soils. The subsequent acid solution removes mineralsoils left behind by the alkaline cleaning step. The strength of thealkaline and acid solutions and the duration of the cleaning steps aretypically dependent on the durability of the soil. The water rinseremoves any residual solution and soils, and cleans the surface prior tothe equipment being returned on-line. The present invention provides apre-treatment step, prior to the CIP process, which penetrates into thesoil. The penetrating materials soften the soil, act as a catalyst, orotherwise enhance the activity of the conventional CIP solution when itcontacts the soil. Thus, the pre-treatment facilitates the soil removal.

Referring now to FIG. 1, a schematic diagram of process equipment isillustrated at reference numeral 10. Process 10 includes a tank 20,which is the equipment to be cleaned. A feed line 25 supplies thevarious cleaning solutions to tank 20, and a drain line 27 removessolution from tank 20. Operably connected via appropriate pipes, valves,pumps, etc. is equipment for a CIP process, designated as referencenumeral 30. CIP process 30 includes a tank 35 for retaining the diluteCIP chemistry. Drain line 27 from tank 20 is used to recirculatesolution from tank 20 back to CIP process 30 and tank 35. Process 10also includes equipment for the pre-treatment process, designated asreference numeral 40. Pre-treatment equipment 40 includes a first tank42 and a second tank 44. When two tanks are used, generally one tank,e.g., tank 42, will contain an alkaline pre-treatment and the othertank, e.g., tank 44, will contain an acidic pre-treatment. Theappropriate pipes, valves, pumps, etc. are in place for operablyconnecting tanks 42, 44 with feed line 25 into tank 20. This set-up ofprocess 10 allows a pre-treatment to be applied to tank 20 without theuse of large amounts of additional equipment, such as piping. Additionaldetails regarding the method of cleaning tank 20 is described below.

The Pre-Treatment Solution

As described above, the pre-treatment solution or pre-treatment step isapplied to the soil prior to the application of conventional CIPchemistries. The chemistry of the pre-treatment solution is selected tofacilitate removal of the soils on the surfaces to be cleaned. Thepre-treatment solution pre-coats and penetrates into the soil, softeningthe soil. The specific chemistry used can be selected based on the soilto be removed. The chemistry used can be compatible with the CIPchemistry. In some embodiments, it is desired to have a pre-treatmentthat is incompatible with the CIP chemistry; in such instances, thepre-treatment reacts with the CIP chemistry. It has been found thatusing incompatible chemistries further increases the soil-removaleffectiveness.

The pre-treatment solution comprises 0.25% of active ingredients, insome cases at least 0.5%, preferably at least 2% and more preferably atleast 3%. By use of the term “active ingredients” what is intended isthe non-inert ingredients that facilitate the softening, dissolving andremoval of soil. These active ingredients include any alkaline/base,acid, penetrant (including surfactant), builder, oxidizer, catalyst andchelant or chelating agent. In most embodiments, water is the remainderof the solution. Typically, the solution has no more than about 15%active ingredients, preferably no more than about 10%. For mostapplications, a concentration of about 1-10% is preferred; aconcentration of about 1-3% is suitable for most applications.

Alkaline or Acidic Ingredients

The pre-treatment solution optionally and preferably includes alkalineor acidic ingredients. Examples of suitable alkaline sources includebasic salts, amines, alkanol amines, carbonates and silicates.Particularly preferred alkaline sources include NaOH (sodium hydroxide),KOH (potassium hydroxide), TEA (triethanol amine), DEA (diethanolamine), MEA (monoethanolamine), sodium carbonate, and morpholine, sodiummetasilicate and potassium silicate.

Examples of suitable acidic sources include mineral acids (such asphosphoric acid, nitric acid, sulfuric acid), and organic acids (such aslactic acid, acetic acid, hydroxyacetic acid, citric acid, glutamicacid, glutaric acid, and gluconic acid).

The amount of alkaline or acid in the pre-treatment solution in somecases is at least 0.25 wt-% and no greater than 10 wt-%. Suitable levelsof alkaline or acid include 2 to 5 wt-% and 0.5 to 1.5 wt-%.

Penetrants

A penetrant may be present in the pre-treatment solution. The penetrantmay be combined with an alkaline or acid source in the solution, or, thepenetrant may be used without an alkaline or acid source. Preferably,the penetrant is water miscible.

Examples of suitable penetrants include alcohols, short chainethoxylated alcohols and phenol (having 1-6 ethoxylate groups). Organicsolvents are also suitable penetrants. Examples of suitable organicsolvents, for use as a penetrant, include esters, ethers, ketones,amines, and nitrated and chlorinated hydrocarbons.

Another preferred class of penetrants is ethoxylated alcohols. Examplesof ethoxylated alcohols include alkyl, aryl, and alkylaryl alkloxylates.These alkloxylates can be further modified by capping with chlorine-,bromine-, benzyl-, methyl-, ethyl-, propyl-, butyl- and alkyl-groups. Apreferred level of ethoxylated alcohols in the solution is 1 to 20 wt-%.

Another class of penetrants is fatty acids. Some non-limiting examplesof fatty acids are C₆ to C₁₂ straight or branched fatty acids. Preferredfatty acids are liquid at room temperature.

Another class of preferred solvents for use as penetrants is glycolethers, which are water soluble. Examples of glycol ethers includedipropylene glycol methyl ether (available under the trade designationDOWANOL DPM from Dow Chemical Co.), diethylene glycol methyl ether(available under the trade designation DOWANOL DM from Dow ChemicalCo.), propylene glycol methyl ether (available under the tradedesignation DOWANOL PM from Dow Chemical Co.), and ethylene glycolmonobutyl ether (available under the trade designation DOWANOL EB fromDow Chemical Co.). A preferred level of glycol ether in the solution is0.5 to 20 wt-%.

Surfactants also are a suitable penetrant for use in the pre-treatmentsolution. Examples of suitable surfactants include nonionic, cationic,and anionic surfactants. Nonionic surfactants are preferred. Nonionicsurfactants improve soil removal and can reduce the contact angle of thesolution on the surface being treated. Examples of suitable nonionicsurfactants include alkyl-, aryl-, and arylalkyl-, alkoxylates,alkylpolyglycosides and their derivatives, amines and their derivatives,and amides and their derivatives. Additional useful nonionic surfactantsinclude those having a polyalkylene oxide polymer as a portion of thesurfactant molecule. Such nonionic surfactants include, for example,chlorine-, benzyl-, methyl-, ethyl-, propyl-, butyl- and other likealkyl-capped polyoxyethylene and/or polyoxypropylene glycol ethers offatty alcohols; polyalkylene oxide free nonionics such as alkylpolyglycosides; sorbitan and sucrose esters and their ethoxylates;alkoxylated ethylene diamine; carboxylic acid esters such as glycerolesters, polyoxyethylene esters, ethoxylated and glycol esters of fattyacids, and the like; carboxylic amides such as diethanolaminecondensates, monoalkanolamine condensates, polyoxyethylene fatty acidamides, and the like; and ethoxylated amines and ether amines and otherlike nonionic compounds. Silicone surfactants can also be used.

Additional suitable nonionic surfactants having a polyalkylene oxidepolymer portion include nonionic surfactants of C₆-C₂₄ alcoholethoxylates having 1 to about 20 ethylene oxide groups; C₆-C₂₄alkylphenol ethoxylates having 1 to about 100 ethylene oxide groups;C₆-C₂₄ alkylpolyglycosides having 1 to about 20 glycoside groups; C₆-C₂₄fatty acid ester ethoxylates, propoxylates or glycerides; and C₄-C₂₄mono or dialkanolamides.

If a surfactant is used as a penetrant, the amount of surfactant in thepre-treatment solution is typically at least 0.25%. Acceptable levels ofsurfactant include 0.4 to 8 wt-%, and 1 to 4 wt-%.

Overall, when an alkaline or acid source is present, the amount ofpenetrant in the pre-treatment solution is at least 0.2 wt-% and nogreater than 2.5 wt-%. Acceptable levels of penetrant, when an alkalineor acid source is present, include 0.4-2 wt-%; 1-2 wt-% is preferred.The amount of penetrant, in relation to any alkaline or acid source whenpresent, is generally 1:1 to 1:5.

For pre-treatment solutions without an alkaline or acid source, theamount of penetrant in the solution is at least 0.05 wt-% and no greaterthan 50%. Generally, the level is 0.1 to 25 wt-%. Acceptable levels ofpenetrant include 0.5 to 10 wt-%, and 1 to 5 wt-%.

Oxidizers

Pre-treatment solutions may include an oxidizing agent or an oxidizer,such as a peroxide or peroxyacid. The resulting solution is veryeffective against protein and starch soils. Further, reaction of theseoxygen compounds with the soil, especially when combined with analkaline source, creates vigorous mechanical action on and within thesoil, which enhances removal of the soil beyond that caused by thechemical and bleaching action.

Suitable ingredients are oxidants such as chlorites, bromine, bromates,bromine monochloride, iodine, iodine monochloride, iodates,permanganates, nitrates, nitric acid, borates, perborates, and gaseousoxidants such as ozone, oxygen, chlorine dioxide, chlorine, sulfurdioxide and derivatives thereof. Peroxygen compounds, which includeperoxides and various percarboxylic acids, including percarbonates, aresuitable.

Peroxycarboxylic (or percarboxylic) acids generally have the formulaR(CO₃H)_(n), where, for example, R is an alkyl, arylalkyl, cycloalkyl,aromatic, or heterocyclic group, and n is one, two, or three, and namedby prefixing the parent acid with peroxy. The R group can be saturatedor unsaturated as well as substituted or unsubstituted. Medium chainperoxycarboxylic (or percarboxylic) acids can have the formulaR(CO₃H)_(n), where R is a C₅-C₁₁ alkyl group, a C₅-C₁₁ cycloalkyl, aC₅-C₁₁ arylalkyl group, C₅-C₁₁ aryl group, or a C₅-C₁₁ heterocyclicgroup; and n is one, two, or three. Short chain fatty acids can have theformula R(CO₃H)_(n) where R is C₁-C₄ and n is one, two, or three.

Some peroxycarboxylic acids include peroxypentanoic, peroxyhexanoic,peroxyheptanoic, peroxyoctanoic, peroxynonanoic, peroxyisononanoic,peroxydecanoic, peroxyundecanoic, peroxydodecanoic, peroxyascorbic,peroxyadipic, peroxycitric, peroxypimelic, or peroxysuberic acid,mixtures thereof, or the like.

Branched chain peroxycarboxylic acid include peroxyisopentanoic,peroxyisononanoic, peroxyisohexanoic, peroxyisoheptanoic,peroxyisooctanoic, peroxyisonananoic, peroxyisodecanoic,peroxyisoundecanoic, peroxyisododecanoic, peroxyneopentanoic,peroxyneohexanoic, peroxyneoheptanoic, peroxyneooctanoic,peroxyneononanoic, peroxyneodecanoic, peroxyneoundecanoic,peroxyneododecanoic, mixtures thereof, or the like.

Typical peroxygen compounds include hydrogen peroxide (H₂O₂), peraceticacid, peroctanoic acid, a persulphate, a perborate, or a percarbonate.

The amount of oxidant in the pre-treatment solution is at least 0.01wt-% and no greater than 1 wt-%. Acceptable levels of oxidant are 0.01to 0.50 wt-%; 0.3 wt-% is a particularly suitable level. Suitable levelsof oxidant, in relation to any acid source, are generally 1:1 to 1:10,1:3 to 1:7, or 1:20 to 1:50. Solutions of 0.25 wt-% to 10 wt-%phosphoric acid with 50-5000 ppm (0.005 wt-% to 0.5 wt-%) hydrogenperoxide are particularly suitable. An example pre-treatment solutionincludes 0.75 wt-% phosphoric acid and 500 ppm (0.05 wt-%) hydrogenperoxide, which is a 1:15 ratio of oxidant:acid.

Builders

The pre-treatment solution preferably includes a builder. Buildersinclude chelating agents (chelators), sequestering agents(sequestrants), detergent builders, and the like. The builder oftenstabilizes the composition or solution. Examples of builders includephosphonic acids and phosphonates, phosphates, aminocarboxylates andtheir derivatives, pyrophosphates, polyphosphates, ethylenediamene andethylenetriamene derivatives, hydroxyacids, and mono-, di-, andtri-carboxylates and their corresponding acids. Other builders includealuminosilicates, nitroloacetates and their derivatives, and mixturesthereof. Still other builders include aminocarboxylates, including saltsof ethylenediaminetetraacetic acid (EDTA),hydroxyethylenediaminetetraacetic acid (HEDTA), anddiethylenetriaminepentaacetic acid. Preferred builders are watersoluble.

Particularly preferred builders include EDTA (including tetra sodiumEDTA), TKPP (tripotassium polyphosphate), PAA (polyacrylic acid) and itssalts, phosphonobutane carboxylic acid, and sodium gluconate.

The amount of builder in the pre-treatment solution, if present, istypically at least 0.25 wt-% and no greater than 5 wt-%. Acceptablelevels of builder include 0.5 to 1.0 wt-% and 1 wt-% to 2.5 wt-%.

Methods of Pre-Treating

The method of the present invention is directed to applying thepre-treatment solution to the surface to be cleaned, prior to aconventional CIP process. The resulting CIP process requires less stepsand/or less time for each step. For example, a conventional CIP processincludes five steps after an initial water rinse: a conventionalalkaline (NaOH) wash to remove soil, an interim rinse, a conventionalacid wash to remove minerals and scale, a water rinse, and aconventional sanitizing step. This process can be replaced with athree-step process after the initial water rinse: A pre-treatment step,a conventional wash, and a water rinse.

By using either of the two pre-treatment processes described immediatelyabove, the amount of water used in the overall cleaning process withpre-treatment is reduced by about 30% or more compared to theconventional five-step process. The amount of time for the overallprocess with pre-treatment is reduced by about 30% or more compared tothe conventional five-step process. The specific number of steps, thewater usage, or the processing time reduced will depend on theconcentration and chemistry of the pre-treatment solution.

Referring again to FIG. 1, pre-treatment solution is stored at theequipment designated as 40. In this process 10, tank 42 holds analkaline pre-treatment solution and tank 44 holds an acidicpre-treatment solution that includes peroxide.

To clean 20, tank 20 and its connection lines are drained of any productthat may be present. A water rinse may be included to remove anyresidual product. In one embodiment, alkaline pre-treatment solutionfrom tank 42 is pumped via piping and feed line 25 into tank 20.Conventional CIP application equipment, such as a spray head, appliesthe pre-treatment solution onto the interior surface of tank 20. Thepre-treatment solution cascades or otherwise flows down the surface oftank 20, softening the soil. A second application of pre-treatmentsolution may be applied, although this is not generally needed.

After application and draining of the pre-treatment solution, aconventional CIP process, using the detergent from process 30 and tank35, is performed. The CIP detergent may be acidic or alkaline. Detergentfrom tank 35 is recirculated through tank 20 via feed line 25, returnline 27, and other appropriate piping.

In another embodiment, a pre-treatment solution containing hydrogenperoxide from tank 44 is pumped via piping and feed line 25 into tank20. After application and draining of the peroxide pre-treatmentsolution, a conventional CIP process, using an alkaline detergent suchas sodium hydroxide, from process 30 and tank 35, is performed. Thesodium hydroxide activates any residual peroxide on the walls of tank20.

When introducing the pre-treatment solution into the CIP process, it maybe beneficial to add the pre-treatment solution at specific placesdepending on the piece of equipment. For example, when treating an HTSTpasteurizer, it is preferable to introduce the pre-treatment solution atthe feed balance tank. Alternatively, the pre-treatment solution can beintroduced on the suction side of the booster pump or at the T or valvelocation just prior to plate assembly. When treating a UHT pasteurizer,it is preferable to introduce the pre-treatment solution at the waterbalance tank. Alternatively, the pre-treatment solution can beintroduced at the product balance or feed tank, or the suction side ofthe booster pump. When treating an evaporator, it is preferable tointroduce the pre-treatment solution on the suction side of the effectrecirculation pump. Alternatively, the pre-treatment solution can beintroduced at the CIP balance tank. Finally, when treating a beerdistillation re-boiler, it is preferable to introduce the pre-treatmentsolution on the suction side of the boiler recirculation pump.Alternatively, the pre-treatment solution can be introduced in thevalves between recirculation pump and the distillation column, or theCIP balance tank. The pre-treatment solution is preferably injectedcloser to the surface to be cleaned. This allows for higher chemicalconcentrations by avoiding dilution of the pre-treatment chemistry bythe entire volume of the CIP supply tank and distribution lines.

Various generic examples of suitable pre-treatment steps are providedbelow.

In one particular example, an alkaline pre-treatment solution of 10 wt-%NaOH is sprayed onto the interior surfaces of a holding tank and allowedto drain. After about 20 minutes, the CIP process, having a 1% acidicsolution, is initiated.

In a second particular example, an acidic pre-treatment solution of 1wt-% phosphoric acid is circulated onto the interior surfaces of aplate-in-frame heat exchanger. The solution includes 0.1 wt-% H₂O₂. Theperoxide is also catalytically activated by a subsequent conventionalalkaline CIP solution which causes further effervescence, formation ofhigh oxidation potential species, and soil removal.

In a third particular example, an acidic pre-treatment solution, havingabout 1.0 wt-% mineral acids and 1.0 wt-% solvent penetrant, iscirculated onto the heat exchanging surfaces of an evaporator anddrained from the surface. After about 20 minutes, the CIP process isinitiated. A conventional alkaline wash, approx. 0.5 wt-% active NaOH,is fed into the evaporator. The alkaline reacts with any acidic residue,generating heat and mechanical action furthering the removal of thesoil.

While the present invention has been discussed primarily in the contextof cleaning surfaces having food and beverage soils, it is understoodthat the invention may be used in applications needing cleaning ingeneral including membranes such as spiral-bound membranes, flat shutceramic membranes used for water filtration or desalinization and heatexchanges surfaces in the chemical and pharmaceutical industries.

For a more complete understanding of the invention, the followingexamples are given to illustrate some embodiments. These examples andexperiments are to be understood as illustrative and not limiting. Allparts are by weight, except where it is contrarily indicated.

EXAMPLES Example 1 Test Procedure

Solid milk pellets were prepared by mixing 3 grams of dry milk power and3 grams of soil. The resulting mix was pressed in a die for 30 secondsat 10,000 lb, and then more pressure was added to again apply 10,000 lbfor 30 additional seconds. The pellets were placed in screens andimmersed in the pre-treatment solutions, described below, for 5 minutes,removed, and then drained for 5 minutes. The screen and dried pelletswere placed in a beaker of 0.5 wt-% NaOH at 120° F. (The test designatedas “None” had no pre-treatment step; the test designated as “None *” hadno pre-treatment step and used a 3.0% NaOH cleaning at 120° F., ratherthan the 0.5% NaOH). The beakers were placed on a hot plate set to 49°C. (approx. 120° F.) with large stir bars rotating at 350 rpm. After 30minutes, the screen and pellets were removed from the cleaning solutionand gently immersed in and removed from deionized water five times, andthen dried overnight in a 50° C. oven. The results of the testing arebelow.

Pre-Treatment 1

A 10 wt-% solution of active NaOH was prepared and used as apre-treatment. The pre-treatment had 100,000 ppm sodium hydroxide (analkaline cleaner).

Pre-Treatment 2

A pre-treatment solution was prepared having 1360 ppm tetra sodium EDTA(a builder and/or chelant), 3000 ppm sodium gluconate (a builder and/orchelant), 2400 ppm potassium silicate (an alkaline cleaner), 7000 ppmalkyl polyglycoside (a surfactant), and 4200 ppm potassium hydroxide (analkaline cleaner). This Pre-Treatment 2 had 3.66% alkaline, 0.43%builder/chelant, and 0.7% surfactant, providing 4.79% activeingredients.

Pre-Treatment 3

A pre-treatment solution was prepared having 41550 ppm polycarboxylatedalcohol ethoxylate (a surfactant), 9540 ppm octyl amine oxide (asurfactant), 25500 ppm alkyl polyglycoside (a surfactant), and 4150 ppm2-ethylhexanol ethoxylate (a penetrant). This Pre-Treatment 3 had 0.4%penetrant and 7.6% surfactant, providing 8% active ingredients.

Pre-Treatment 4

A pre-treatment solution was prepared having 1600 pm potassium hydroxide(an alkaline cleaner), 9465 ppm sodium hydroxide (an alkaline cleaner),18500 ppm polyacrylic acid (a builder and/or chelant), and 4625 ppmphosphonobutane tricarboxylic acid (a builder and/or chelant). ThisPre-Treatment 4 had 1.10% alkaline and 2.3% builder/chelant, providing2.9% active ingredients.

screen + screen + pellet wt, pellet wt, pellet wt pellet wtPre-Treatment Screen wt before clean after clean before after clean % wtloss of solution (g) (g) (g) clean (g) (g) pellet 1 18.23 23.93 22.595.70 4.36 23.51% 1 18.20 23.86 22.52 5.66 4.32 23.67% 2 18.23 23.9122.54 5.68 4.31 24.12% 2 18.02 23.34 22.08 5.32 4.06 23.68% 3 19.2424.70 22.14 5.46 2.90 46.89% 3 18.06 23.67 21.19 5.61 3.13 44.21% 417.95 23.50 20.09 5.55 2.14 61.44% 4 18.22 23.90 21.69 5.68 3.47 38.91%None 19.16 24.81 23.22 5.65 4.06 28.14% None 13.47 18.76 17.22 5.29 3.7529.11% None * 19.27 25.01 24.14 5.74 4.87 15.16% None * 18.15 23.8223.02 5.67 4.87 14.11%

The results show both consistency within the cleaning processes anddifferences when comparing the methods. The results indicate that lowerlevels of NaOH are better than higher levels, and that pre-treatmentsolutions 3 and 4 are superior to pre-treatment solutions

1 and 2. This difference, however, may be due to the test procedureused. Tests 1 and 2 were done on one hot plate whereas tests 3 and 4were done on a second hot plate. It is possible that these two hotplates were not equal at maintaining the 120° F. temperature.

A drastic difference was seen between the duplicate tests (i.e., 61% and39% for solution 4); it is possible that one of the pellets had a crackin it, providing a weak location for the pellet to break. The highexposed surface area would result in an increase rate if disintegration.

The tests were rerun on the same hotplate in an attempt to determine ifthere was any inconsistency between temperature control of thehotplates. The results are provided in the table below, under the columndesignated “% wt loss of pellet with pre-treat”.

As an alternative, and comparative method, 1 gram of the Pre-treatmentsolution were added to 315 grams of the 0.5% NaOH cleaning solution.Thus, rather than applying the pre-treatment chemistry as a separatestep, the pre-treatment chemistry was added to the cleaning solution.The results are provided in the table below, under the column designated“% wt loss of pellet without pre-treat”.

% wt loss of pellet % wt loss of pellet Pre-treatment with pre-treatwithout pre-treat 1 22.16% 36.92% 2 23.90% 37.39% 3 41.96% 34.01% 450.17% 31.95%

The results indicate that eliminating the separate pre-treatment stepand adding the chemicals directly to the cleaning solution increased theperformance of the two less effective solutions (1-10% NaOH; 2-10%KX-3108) and decreased the performance of the two more effectivesolutions (3-10% Quadexx 400; 4-10% Quadexx 500). All of these resultswere better than if no pre-treatment was present (which provided pelletloss of about 29%).

Example 2 Test Procedure

Soiled stainless steel test panels, having soil on one side, wereprepared by drying a mixture of mashed corn solids onto one side of thepanel in an oven at 120° C. for 4 hours. The soiled panels were thencleaned as described below.

For Test (I), with the pre-treatment step, 800 grams of Pre-Treatmentsolution 5 were placed in a 1000 ml beaker. It had been determined thatapproximately 1 gram of the pre-treatment solution contacted andremained on the soiled panel. After a brief dip in the pre-treatment,the panels were hung for 5 minutes in ambient conditions. The driedpanels were then placed in a 1000 ml beaker which had 750 g of 40° C.water with the soil side down. After 30 minutes, the panels were gentlyimmersed in and removed from deionized water five times, and the panelswere then dried. The results of the testing are below.

For Test (II), the test panels were not pre-treated, but were cleaned in750 g of 40° C. water with 1 g Pre-Treatment 5 added to the water.

For Test (III) the test panels were not pre-treated, but were cleaned in750 g of 40° C. water.

Pre-Treatment 5

A pre-treatment solution was prepared having 400 ppm tetra sodium EDTA(a builder and/or chelant), 4500 ppm tri potassium polyphosphate (abuilder and/or chelant), 3852 ppm potassium hydroxide (an alkalinecleaner), 3000 ppm polyethylene phenol ether phosphate (a surfactant),1000 ppm sodium metasilicate (an alkaline cleaner), 9000 ppm ethyleneglycol monobutyl ether (a penetrant), and 2400 ppm sodium xylenesulfonate (a surfactant). This Pre-Treatment 5 had 0.5% alkaline, 0.5%builder/chelant, 0.5% surfactant, and 0.9% penetrant, providing 2.4%active ingredients.

Test Method average % soil removed I 99.12% (average of three tests) II14.14% (average of three tests) III 14.12% (average of two tests)

The results above show that merely adding the pre-treatment chemistry tothe wash solution, does not improve the soil removal from the testpanels. Rather, separated and step-wise application of the pre-treatmentsolution and the wash solution provides improved soil removal.

Example 3

Example 3 tested the effectiveness of various different pre-treatmentand main wash chemistries on removing corn beer thin stillage syrup. Forthis test, the corn beer thin stillage syrup soil was prepared byweighing 3 inch by 5 inch stainless steel screens. A mixture of 85% cornbeer thin stillage syrup and 15% deionized water was prepared and thescreens were dipped in the mixture and set aside to drain the excess for10 minutes. The screens were then baked at 125° C. for 2 hours. Thescreens were re-dipped and baked another 2 times for a total of 3 times.The final screens were weighed again. For cleaning, 1000 mL of thechemical cleaning solutions in Table 1 were heated to 180° F. Thescreens were inserted into the cleaning solution. A stir bar was in thecleaning solution and set at 400 rpm for the entire test (30 minutes).After 30 minutes, the screens were removed and allowed to dry beforeweighing. The percent soil removal was calculated using the followingformula:

${\frac{{{Soiled}\mspace{14mu} {wt}} - {{After}\mspace{14mu} {wt}}}{{{Soiled}\mspace{14mu} {wt}} - {{virgin}\mspace{14mu} {wt}}} \times 100} = {\% \mspace{11mu} {Soil}\mspace{14mu} {Removal}}$

Table 1 shows the percent soil removal of various pre-treatment and mainwash chemistries.

TABLE 1 Pre-treatment Solution Effectiveness On Corn Beer Thin StillageSyrup Exp 15 Min Pre-treatment Chemistry 15 Min CIP Main Wash % Soil #Chemistry Tradename Percent % Chemistry Percent % Removal 1 NaOH 3.00 —— 75.70 2 Na2CO3 2.00 — — 65.00 3 MEA (99%) 4.00 NaOH 3.00 75.00 4 DEA4.00 NaOH 3.00 82.40 5 TEA 4.00 NaOH 3.00 79.50 6 Morpholine 4.00 NaOH3.00 82.60 7 Cyclohexylamine 4.00 NaOH 3.00 84.50 8 n-Methyl Pyrolidone4.00 NaOH 3.00 84.90 9 Monoisopropanol amine 4.00 NaOH 3.00 94.60 10H₂O₂ 0.50 NaOH 3.00 95.00 MEA (99%) 4.00 11 H₂O₂ 0.50 NaOH 3.00 97.40DEA 4.00 12 H₂O₂ 0.50 NaOH 3.00 90.00 TEA 4.00 13 H₂O₂ 0.50 NaOH 3.0089.80 Morpholine 4.00 14 H₂O₂ 0.50 NaOH 3.00 94.80 Cyclohexylamine 4.0015 H₂O₂ 0.50 NaOH 3.00 82.10 n-Methyl Pyrolidone 4.00 16 H₂O₂ 0.50 NaOH3.00 92.70 Monoisopropanol amine 4.00 17 H₂O₂ 0.50 NaOH 3.00 94.90 18Dowanol EB 4.00 NaOH 3.00 96.40 19 Dowanol DM 4.00 NaOH 3.00 84.60 20Dowanol PnB 4.00 NaOH 3.00 97.00 21 Dowanol EpH 4.00 NaOH 3.00 80.20 22Dowanol DpnP 4.00 NaOH 3.00 87.60 23 Dowanol PnP 4.00 NaOH 3.00 86.20 24Dowanol PPh 4.00 NaOH 3.00 84.80 25 Propylene Carbonate 4.00 NaOH 3.0071.90 Dowanol EB 4.00 26 H₂O₂ 0.50 NaOH 3.00 92.00 Dowanol DM 4.00 27H₂O₂ 0.50 NaOH 3.00 96.50 Dowanol PnB 4.00 28 H₂O₂ 0.50 NaOH 3.00 97.00Dowanol EpH 4.00 29 H₂O₂ 0.50 NaOH 3.00 94.20 Dowanol DpnP 4.00 30 H₂O₂0.50 NaOH 3.00 99.00 Dowanol PnP 4.00 31 H₂O₂ 0.50 NaOH 3.00 98.80Dowanol PPh 4.00 32 H₂O₂ 0.50 NaOH 3.00 99.20 Propylene Carbonate 4.0033 H₂O₂ 0.50 NaOH 3.00 88.4 34 Dequest 2000 4.00 NaOH 3.00 89.30 35Dequest 2010 4.00 NaOH 3.00 86.20 36 EDTA 4.00 NaOH 3.00 89.20 37 STPP4.00 NaOH 3.00 79.70 38 TKPP 4.00 NaOH 3.00 89.10 39 Sodium Gluconate4.00 NaOH 3.00 89.50 Dequest 2000 4.00 40 H₂O₂ 0.50 NaOH 3.00 95.30Dequest 2010 4.00 41 H₂O₂ 0.50 NaOH 3.00 94.10 EDTA 4.00 42 H₂O₂ 0.50NaOH 3.00 95.00 STPP 4.00 43 H₂O₂ 0.50 NaOH 3.00 95.00 TKPP 4.00 44 H₂O₂0.50 NaOH 3.00 97.00 Sodium Gluconate 4.00 45 H₂O₂ 0.50 NaOH 3.00 93.00

Example 4

Example 4 compared the ability of various oxidizers to remove corn beerthin stillage syrup. For this example, the screens were soiled with cornbeer thin stillage syrup and cleaned as described in Example 3. Table 2shows the impact of various oxidizers on soil removal.

TABLE 2 Impact of Oxidizers on Corn Beer Thin Stillage Syrup Removal 15Min Pre-treatment 15 Min CIP Main % Soil Exp # Chemistry Percent % WashChemistry Percent % Removal 1 H₂O₂ 0.50 NaOH 3.00 94.90 2 SodiumPerborate 1.50 NaOH 3.00 96.40 3 Sodium Percarbonate 1.75 NaOH 3.0082.80 4 Sodium Persulfate 3.38 NaOH 3.00 72.30 5 Potassium Permanganate1.12 NaOH 3.00 93.90

Example 5

Example 5 compared the amount of time it took to clean the screens usingthe pre-treatment solutions of the present invention compared to usingonly sodium hydroxide. This example tested the time to clean on cornbeer thin stillage syrup and whole milk soil. The corn beer thinstillage syrup soil was prepared and cleaned as described in Example 3.

For the whole milk soil, the soil was prepared by weighing stainlesssteel discs to be soiled and affixing the disk to the bottom of a 1.5foot, 3 inch diameter stainless steel tube. A water bath was heated to205° F. to 210° F. and the tubes with the discs were placed in the waterbath. A ⅓ gallon of whole milk was added to each tube used and allowedto sit for 4 hours. After 4 hours, the disks were removed and allowed todry for at least 48 hours before weighing. When cleaning the whole milksoil, the disc was affixed to an overhead stirrer. The desired cleaningsolution was heated to 180° F. using a hot plate. The disc was insertedinto a 1 L beaker of cleaning solution for 10 minutes and the overheadstirrer was set to 50 rpm. After 10 minutes, the disc was removed fromthe cleaning solution and placed in a beaker of deionized water. Theoverhead stirrer was set at 200 rpm for 30 seconds. The disc was removedand allowed to dry at least 48 hours before weighing. The percent soilremoval was calculated using the following formula:

${\frac{{{Soiled}\mspace{14mu} {wt}} - {{After}\mspace{14mu} {wt}}}{{{Soiled}\mspace{14mu} {wt}} - {{virgin}\mspace{14mu} {wt}}} \times 100} = {\% \mspace{11mu} {Soil}\mspace{14mu} {Removal}}$

Tables 3 and 4 show the time it took to remove 100% of the soil on thescreen or disc when using sodium hydroxide alone, Stabicip Oxipre-treatment followed by a sodium hydroxide wash, and Formula A (74%hydrogen peroxide (35%), 9.75% sodium cumene sulfonate (40%), 5.25%sodium octane sulfonate, 3.50% hydroxyethylidene diphosphonic acid(60%), 3% methane sulfonic acid, 1% n-butyl capped alcohol ethoxylate(5EO), and 3.5% pelargonic acid) followed by a sodium hydroxide wash.Stabicip Oxi is a hydrogen peroxide based composition commerciallyavailable from Ecolab Inc. (St. Paul, Minn.).

TABLE 3 Time to Clean Corn Beer Thin Stillage Syrup Soil 15 Min CIP 15Min Pre-treatment Main Wash Time (Min) to 100% Exp # Chemistry Percent %Chemistry Percent % Soil Removal 1 NaOH 2.00 — — 60 2 Stabicip Oxi 1.50NaOH 2.00 30

Table 3 shows that including a hydrogen peroxide based pre-treatmentcomposition together with a sodium hydroxide wash cuts the time to cleancorn beer thin stillage syrup in half when compared to a sodiumhydroxide wash alone.

TABLE 4 Time to Clean Whole Milk Soil 15 Min CIP 15 Min Pre-treatmentMain Wash Time (Min) to 100% Exp # Chemistry Percent % Chemistry Percent% Soil Removal 1 NaOH 2.00 — — >60 min 2 Stabicip Oxi 1.50 NaOH 2.00 333 Formula A 1.50 NaOH 2.00 27Table 4 shows that including a hydrogen peroxide based pre-treatmentcomposition together with a sodium hydroxide wash cuts the time to cleanwhole milk soil in half when compared to a sodium hydroxide wash alone.Using Formula A together with a sodium hydroxide wash cuts the time toclean whole milk soil by more than half when compared to sodiumhydroxide wash alone.

Example 6

Example 6 tested the effectiveness of various different pre-treatmentand main wash chemistries on the removal of whole milk soil. For thistest, the whole milk soil was prepared and cleaned as described inExample 5. Table 5 shows the percent removal of the variouscombinations.

TABLE 5 Pre-treatment Solution Effectiveness On Whole Milk 5 Min CIP 5Min Pre-treatment Chemistry Main Wash % Soil Exp # Chemistry TradenamePercent % Chemistry Percent % Removal 1 NaOH 1.00 — — 37.90 2 MEA (99%)0.50 — — 23.00 3 Dowanol EB 0.50 — — 9.70 4 HP Add 6 * 0.50 — — 10.80 5Stabicip Oxi 0.50 — — 12.60 6 HNO₃ 0.50 — — 20.00 7 Dowanol EB 0.50 NaOH1.00 34.50 8 Stabicip Oxi 0.50 NaOH 1.00 57.50 9 HP Add 6 * 0.50 NaOH1.00 47.20 10 MEA (99%) 0.50 NaOH 1.00 41.80 11 HNO₃ 0.50 NaOH 1.0049.20 12 MEA (99%) 0.50 H2O2 0.15 19.90

The invention has been described with reference to various specific andpreferred embodiments and techniques. However, it should be understoodthat many variations and modifications may be made while remainingwithin the spirit and scope of the invention.

1.-12. (canceled)
 13. A method for cleaning soil from industrialequipment using a CIP process, the method comprising: (a) applying apre-treatment solution to the soil, the solution comprising at least0.25 wt % active ingredients, the active ingredients comprising: abuilder selected from the group consisting of sodium gluconate; apolyphosphate; a phosphonic acid; phosphono-1,2,4-tricarboxylic acid andmixtures thereof, and an oxidizer selected from the group consisting ofhydrogen peroxide, peroxycarboxylic acids, and mixtures thereof, and (b)circulating a second solution through the equipment, the second solutioncomprising a dilute alkaline detergent, wherein there is no rinse stepbetween the application of the pre-treatment solution and the secondsolution; and (c) rinsing the equipment.
 14. The method of claim 13,wherein the builder is present in an amount of at least about 0.25 wt %.15. The method of claim 14, wherein the builder is sodium gluconate. 16.The method of claim 13, wherein the oxidizer is present in an amount ofabout 0.01 wt-% to about 1 wt-%.
 17. The method of claim 16, wherein theoxidizer is hydrogen peroxide.
 18. The method of claim 13, wherein thepre-treatment solution further comprises about 0.25 wt-% to about 10wt-% of an organic acid.
 19. The method of claim 18, wherein the organicacid is selected from the group consisting of pelargonic acid,methanesulfonic acid, hydroxyethylidene diphosphonic acid, gluconic acidand mixtures thereof.
 20. The method of claim 19, wherein thepre-treatment solution further comprises about 0.4 wt-% to about 8.0wt-% of a penetrant.
 21. The method of claim 20, wherein the penetrantcomprises an alkyl capped polyoxyethylene glycol ether.
 22. The methodof claim 21, wherein the pre-treatment solution comprises: (a) sodiumgluconate; (b) hydrogen peroxide; (c) hydroxyethylidene diphosphoicacid; (d) pelargonic acid; and (e) n-butyl capped alcohol ethoxylate(5EO).
 23. The method of claim 22, wherein the pre-treatment solutionfurther comprises methanesulfonic acid.
 24. The method of claim 22,wherein the pre-treatment solution further comprises a mineral acid. 25.The method of claim 24, wherein the mineral acid is phosphoric acid. 26.A method for cleaning soil from industrial equipment using a CIPprocess, the method comprising: (a) applying a pre-treatment solution tothe soil, the solution comprising at least 0.25 wt % active ingredients,the active ingredients comprising: an oxidizer selected from the groupconsisting of hydrogen peroxide, peroxycarboxylic acids, and mixturesthereof, and an acid selected from the group consisting of mineralacids, organic acids, and mixtures thereof, (b) circulating a secondsolution through the equipment, the second solution comprising a dilutealkaline detergent, wherein there is no rinse step between theapplication of the pre-treatment solution and the second solution; and(c) rinsing the equipment.
 27. The method of claim 26, wherein theorganic acid is selected from the group consisting of gluconic acid,pelargonic acid, methanesulfonic acid, hydroxyethylidene diphosphonicacid, and mixtures thereof.
 28. The method of claim 27, wherein theorganic acid is gluconic acid.
 29. The method of claim 27, wherein thepre-treatment solution further comprises a builder selected from thegroup consisting of sodium gluconate; a polyphosphate; a phosphonicacid; phosphono-1,2,4-tricarboxylic acid and mixtures thereof.
 30. Themethod of claim 29, wherein the builder is sodium gluconate.
 31. Themethod of claim 26, wherein the mineral acid is phosphoric acid.
 32. Themethod of claim 26, wherein the pretreatment solution further comprisesan alkaline source.
 33. The method of claim 32, wherein the alkalinesource is sodium carbonate.
 34. The method of claim 32, wherein thealkaline source is selected from the group consisting of potassiumhydroxide, sodium hydroxide, and mixtures thereof.
 35. The method ofclaim 34, wherein the pre-treatment solution further comprises apolyphosphate.